Antiferromagnetic order and its interplay with superconductivity in CaK(Fe1-xMnx)4As4.

The magnetic order for several compositions of CaK(Fe1-xMnx)4As4has been studied by nuclear magnetic resonance (NMR), Mössbauer spectroscopy, and neutron diffraction. Our observations for the Mn-doped 1144 compound are consistent with the hedgehog spin vortex crystal (hSVC) order which has previously been found for Ni-dopedCaKFe4As4. The hSVC state is characterized by the stripe-type propagation vectors(π0)and(0π)just as in the doped 122 compounds. The hSVC state preserves tetragonal symmetry at the Fe site, and only this SVC motif with simple antiferromagnetic (AFM) stacking alongcis consistent with all our observations using NMR Mössbauer spectroscopy, and neutron diffraction. We find that the hSVC state in the Mn-doped 1144 compound coexists with superconductivity, and by combining the neutron scattering and Mössbauer spectroscopy data we can infer a quantum phase transition, hidden under the superconducting dome, associated with the suppression of the AFM transition temperature (TN) to zero forx ≈ 0.01. In addition, unlike several 122 compounds and Ni-doped 1144, the ordered magnetic moment is not observed to decrease at temperatures below the superconducting transition temperature (Tc).

Differential Hepatotoxic Effects of Sodium Valproate at Different Doses in Albino Rats.

Background Liver plays an essential role for transforming and clearing chemicals that may cause harmful effects to it. Sodium Valproate, renowned to be a potent antiepileptic drug, when taken in overdose may cause toxic effects to liver and other organs as well. Liver damage can be assessed with histological changes and measurement of enzymes produced by it. Objective To investigate the histological changes induced by different doses of Sodium Valproate ranging from 100-500 mg/kg/day and observe its correlation with liver enzymes level in serum. Method Three-months old albino rats were divided into six groups, five in each. Control group was treated with normal saline and rest five groups with Sodium Valproate in different doses 100, 200, 300, 400 and 500 mg/kg/day respectively. Then, liver of those experimented rats were examined histologically under the light microscope. Furthermore, Liver enzymes; Alanine Transaminase and Aspartate transaminase were measured to assess the micro-anatomical changes in liver. Result Distorted hepatic lobular architecture with aggregations of nuclei at certain interval was observed in the groups of higher doses; 300 mg/kg/day and above. However, accumulation of adipocytes was observed in all the Sodium Valproate treated rats unlike the control group. When compared the enzyme levels among the groups, it was found to be significantly increased in dose dependent manner. Besides, it also showed skin lesions in all rats treated with the dose 400 mg/kg/day and above. Conclusion Higher doses of Sodium Valproate; 300 mg/kg/day and above induces hepatotoxicity and skin lesions in adult albino rats.

Effective One-Dimensional Coupling in the Highly Frustrated Square-Lattice Itinerant Magnet CaCo_{2-y}As_{2}.

Inelastic neutron scattering measurements on the itinerant antiferromagnet CaCo_{2-y}As_{2} at a temperature of 8 K reveal two orthogonal planes of scattering perpendicular to the Co square lattice in reciprocal space, demonstrating the presence of effective one-dimensional spin interactions. These results are shown to arise from near-perfect bond frustration within the J_{1}-J_{2} Heisenberg model on a square lattice with ferromagnetic J_{1} and hence indicate that the extensive previous experimental and theoretical study of the J_{1}-J_{2} Heisenberg model on local-moment square spin lattices should be expanded to include itinerant spin systems.

Association between wetland presence and incidence of Salmonella enterica serotype Javiana infections in selected US sites, 2005-2011.

Salmonella causes an estimated 1·2 million illnesses annually in the USA. Salmonella enterica serotype Javiana (serotype Javiana) is the fourth most common serotype isolated from humans, with the majority of illnesses occurring in southeastern states. The percentage of wetland cover by wetland type and the average incidence rates of serotype Javiana infection in selected counties of the Foodborne Disease Active Surveillance Network (FoodNet) were examined. This analysis explored the relationship between wetland environments and incidence in order to assess whether regional differences in environmental habitats may be associated with observed variations in incidence. Findings suggest that environmental habitats may support reservoirs or contribute to the persistence of serotype Javiana, and may frequently contribute to the transmission of infection compared with other Salmonella serotypes.

Effect of Biaxial Strain on the Phase Transitions of Ca(Fe_{1-x}Co_{x})_{2}As_{2}.

We study the effect of applied strain as a physical control parameter for the phase transitions of Ca(Fe_{1-x}Co_{x})_{2}As_{2} using resistivity, magnetization, x-ray diffraction, and ^{57}Fe Mössbauer spectroscopy. Biaxial strain, namely, compression of the basal plane of the tetragonal unit cell, is created through firm bonding of samples to a rigid substrate via differential thermal expansion. This strain is shown to induce a magnetostructural phase transition in originally paramagnetic samples, and superconductivity in previously nonsuperconducting ones. The magnetostructural transition is gradual as a consequence of using strain instead of pressure or stress as a tuning parameter.

Testing the feasibility of using a conveyor belt to load weanling and nursery pigs for transportation.

Transportation is known to be a multi-faceted stressor, with the process of loading being one of the most significant factors impacting the stress to which animals are exposed. This project was designed to determine if using a conveyor to load pigs into the top deck of a simulated straight deck trailer could lower the stress to which pigs and handlers are exposed. Pigs were assigned to either a Control group that were herded up a stationary conveyor ramp into a top deck trailer (2.5 m above the ground); or Conveyor group which were herded onto a mobile conveyor into a top deck trailer. The conveyor was 7.6 m long, 0.9 m wide and rose to 2.5 m high at a 16° slope, and moved 11.3 m/min. Two age groups were tested; Weanling pigs which were moved in groups of 20 (n = 14 groups/treatment) and Nursery pigs which were moved in groups of 10 (n = 15 groups/treatment). Behavior was recorded during loading, including slips and falls, vocalizations, assists, and time to load. Heart rate of 2 sentinel pigs/group and the handler were recorded during loading, and body temperature of the handler after loading. Pigs were held in the simulated trailer for 30 min while heart rate was recorded. After which, they were unloaded and held in a holding pen for an additional 30 min while heart rate was recorded. There were no treatment differences for slips or falls (P < 0.90). Vocalizations were too few to analyze. Both Weanling (2.8 ± 0.7) and Nursery (1.6 ± 0.5) Conveyor pigs needed to be assisted onto the conveyor more than Weanling (1.2 ± 0.4) and Nursery (0.3 ± 0.1) Control pigs (P < 0.06). There was no difference in total loading time between the treatments for any age group (P < 0.15), with Weanling and Nursery pigs loading in 50 to 45 s, respectively. There were no treatment differences for heart rate variability measures (P > 0.10). However, loading increased heart rate of Nursery pigs (204.9 ± 5.7 bpm, P < 0.005), but not Weanling pigs (172.1 ± 9.0 bpm). Nursery pigs had a greater ratio of low frequency to high frequency power during loading (P < 0.02) compared to other phases of the procedure in both Control and Conveyor groups. Heart rate (93.9 ± 1.9 bpm) and body temperature (31.1 ± 0.3°C, eye temperature) of the handler was not affected by treatment (P < 0.26). Based on behavior and physiology, the pigs had similar experiences in both treatments. This study shows that it is feasible to use a conveyor to load pigs, but it may not be advantageous.

Strong cooperative coupling of pressure-induced magnetic order and nematicity in FeSe.

A hallmark of the iron-based superconductors is the strong coupling between magnetic, structural and electronic degrees of freedom. However, a universal picture of the normal state properties of these compounds has been confounded by recent investigations of FeSe where the nematic (structural) and magnetic transitions appear to be decoupled. Here, using synchrotron-based high-energy x-ray diffraction and time-domain Mössbauer spectroscopy, we show that nematicity and magnetism in FeSe under applied pressure are indeed strongly coupled. Distinct structural and magnetic transitions are observed for pressures between 1.0 and 1.7 GPa and merge into a single first-order transition for pressures ≳1.7 GPa, reminiscent of what has been found for the evolution of these transitions in the prototypical system Ba(Fe1-xCox)2As2. Our results are consistent with a spin-driven mechanism for nematic order in FeSe and provide an important step towards a universal description of the normal state properties of the iron-based superconductors.

Including dietary fiber and resistant starch to increase satiety and reduce aggression in gestating sows.

Aggression during mixing of pregnant sows impacts sow welfare and productivity. The aim of this study was to increase satiety and reduce aggression by including dietary fiber and fermentable carbohydrates. Sows were housed in individual stalls 7 to 14 d after breeding (moving day was considered d 0 of treatment) and were fed (at 0700 h) with a CONTROL (corn-soybean meal based with no additional fiber sources), RSTARCH (10.8% resistant starch), BEETPULP (27.2% sugar beet pulp), SOYHULLS (19.1% soybean hulls), or INCSOY (14.05% soybean hulls) for 21 d (5 sows/diet × 5 diets × 8 replications = 200 sows). The CONTROL diet was targeted to contain 185 g(d∙sow) NDF and the other diets were targeted to contain 350 g(d∙sow) NDF. The INCSOY diet was fed at 2.2 kg/(d∙sow) and the other diets were fed at 2 kg(d∙sow). On d 22, sows were mixed in groups of 5 (at 1200 h). Behaviors in stalls (on d 1, 7, 14, and 21) and after mixing (d 22 and 23), heart rate (on d 1, 7, 14, and 21), blood metabolites (on d 2, 8, 15, 22, and 25), and the effects of diets on production were collected and analyzed. Sows stood more ( < 0.01) and rested less ( < 0.001) over time irrespective of the diet. Sows on BEETPULP stood more ( < 0.01) and sows on SOYHULLS rested more ( < 0.01). Sham chewing increased over days irrespective of the diet. Chewing behavior (bar and feeder) increased with days on diet ( < 0.001) and was lowest in sows on the SOYHULLS diet ( = 0.045). When mixed, biting frequency in the first hour was highest for sows on the CONTROL diet (236.5 ± 62.6) and lowest for sows on the RSTARCH diet (90.5 ± 30.5). Skin lesions increased ( < 0.001) 24 h after mixing sows irrespective of diet. Blood urea nitrogen (BUN) concentration was lowest in sows fed BEETPULP and SOYHULLS ( < 0.001). Serum glucose concentration was highest in sows fed RSTARCH and BEETPULP ( = 0.04), but there was no day effect ( = 0.62) or diet × day interaction ( = 0.60). The NEFA was greatest in sows fed RSTARCH, BEETPULP, and SOYHULLS ( < 0.001). Lactate ( < 0.001) and BUN concentrations were greatest on d 2 but dropped and remained constant after d 8. Average heart rate was lowest for sows on SOYHULLS and INCSOY compared with sows on the other diets ( = 0.03). Number of piglets born and average weaning weight were not affected by diets ( > 0.05). Average birth weight was lowest in the INCSOY diet ( = 0.02). This study demonstrates that RSTARCH and SOYHULLS can improve the welfare of sows by reducing aggression and increasing satiety in limit-fed pregnant sows without affecting production.

Discovery of an Unconventional Charge Density Wave at the Surface of K_{0.9}Mo_{6}O_{17}.

We use angle resolved photoemission spectroscopy, Raman spectroscopy, low energy electron diffraction, and x-ray scattering to reveal an unusual electronically mediated charge density wave (CDW) in K_{0.9}Mo_{6}O_{17}. Not only does K_{0.9}Mo_{6}O_{17} lack signatures of electron-phonon coupling, but it also hosts an extraordinary surface CDW, with T_{S_CDW}=220 K nearly twice that of the bulk CDW, T_{B_CDW}=115 K. While the bulk CDW has a BCS-like gap of 12 meV, the surface gap is 10 times larger and well in the strong coupling regime. Strong coupling behavior combined with the absence of signatures of strong electron-phonon coupling indicates that the CDW is likely mediated by electronic interactions enhanced by low dimensionality.

Development of three-dimensional integrated microchannel-electrode system to understand the particles' movement with electrokinetics.

An optical transparent 3-D Integrated Microchannel-Electrode System (3-DIMES) has been developed to understand the particles' movement with electrokinetics in the microchannel. In this system, 40 multilayered electrodes are embedded at the 2 opposite sides along the 5 square cross-sections of the microchannel by using Micro Electro-Mechanical Systems technology in order to achieve the optical transparency at the other 2 opposite sides. The concept of the 3-DIMES is that the particles are driven by electrokinetic forces which are dielectrophoretic force, thermal buoyancy, electrothermal force, and electroosmotic force in a three-dimensional scope by selecting the excitation multilayered electrodes. As a first step to understand the particles' movement driven by electrokinetic forces in high conductive fluid (phosphate buffer saline (PBS)) with the 3-DIMES, the velocities of particles' movement with one pair of the electrodes are measured three dimensionally by Particle Image Velocimetry technique in PBS; meanwhile, low conductive fluid (deionized water) is used as a reference. Then, the particles' movement driven by the electrokinetic forces is discussed theoretically to estimate dominant forces exerting on the particles. Finally, from the theoretical estimation, the particles' movement mainly results from the dominant forces which are thermal buoyancy and electrothermal force, while the velocity vortex formed at the 2 edges of the electrodes is because of the electroosmotic force. The conclusions suggest that the 3-DIMES with PBS as high conductive fluid helps to understand the three-dimensional advantageous flow structures for cell manipulation in biomedical applications.

Volatile organic compounds and particulate matter in child care facilities in the District of Columbia: Results from a pilot study.

BACKGROUND: Many young children in the U.S. spend a significant portion of their day in child care facilities where they may be exposed to contaminants linked to adverse health effects. Exposure data on volatile organic compounds (VOCs) and particulate matter (PM) in these settings is scarce. OBJECTIVE: To guide the design of a larger exposure assessment study in urban child care facilities, we conducted a pilot study in which we characterized indoor concentrations of select VOCs and PM. METHODS: We recruited 14 child care facilities in the District of Columbia (Washington, DC) and measured indoor concentrations of seven VOCs (n=35 total samples; 2-5 samples per facility): benzene, carbon tetrachloride, chloroform, ethylbenzene, o-xylene, p-xylene, and toluene in all facilities; and collected real-time PM measurements in seven facilities. We calculated descriptive statistics for contaminant concentrations and computed intraclass correlation coefficients (ICC) to evaluate the variability of VOC levels indoors. We also administered a survey to collect general health information on the children attending these facilities, and information on general housekeeping practices and proximity of facilities to potential sources of target contaminants. RESULTS: We detected six of the seven VOCs in the majority of child care facilities with detection frequencies ranging from 71% to 100%. Chloroform and toluene were detected in all samples. Median (range) concentrations for toluene, chloroform, benzene, o-xylene, ethylbenzene, and carbon tetrachloride were: 5.6µg/m(3) (0.6-16.5µg/m(3)), 2.8µg/m(3) (0.4-53.0µg/m(3)), 1.4µg/m(3) (below the limit of detection or

Itinerant ferromagnetism in the As 4p conduction band of Ba_{0.6}K_{0.4}Mn_{2}As_{2} identified by X-ray magnetic circular dichroism.

X-ray magnetic circular dichroism (XMCD) measurements on single-crystal and powder samples of Ba_{0.6}K_{0.4}Mn_{2}As_{2} show that the ferromagnetism below T_{C}≈100 K arises in the As 4p conduction band. No XMCD signal is observed at the Mn x-ray absorption edges. Below T_{C}, however, a clear XMCD signal is found at the As K edge which increases with decreasing temperature. The XMCD signal is absent in data taken with the beam directed parallel to the crystallographic c axis indicating that the orbital magnetic moment lies in the basal plane of the tetragonal lattice. These results show that the previously reported itinerant ferromagnetism is associated with the As 4p conduction band and that distinct local-moment antiferromagnetism and itinerant ferromagnetism with perpendicular easy axes coexist in this compound at low temperature.

Structural and Magnetic Phase Transitions near Optimal Superconductivity in BaFe2(As(1-x)Px)2.

We use nuclear magnetic resonance (NMR), high-resolution x-ray, and neutron scattering studies to study structural and magnetic phase transitions in phosphorus-doped BaFe2(As(1-x)P(x)2. Previous transport, NMR, specific heat, and magnetic penetration depth measurements have provided compelling evidence for the presence of a quantum critical point (QCP) near optimal superconductivity at x=0.3. However, we show that the tetragonal-to-orthorhombic structural (T{s}) and paramagnetic to antiferromagnetic (AF, TN) transitions in BaFe2(As(1-x)Px)2 are always coupled and approach T{N}≈T{s}≥T{c} (≈29 K) for x=0.29 before vanishing abruptly for x≥0.3. These results suggest that AF order in BaFe_{2}(As(1-x)Px)2 disappears in a weakly first-order fashion near optimal superconductivity, much like the electron-doped iron pnictides with an avoided QCP.

Stripe antiferromagnetic spin fluctuations in SrCo2As2.

Inelastic neutron scattering measurements of paramagnetic SrCo2As2 at T=5 K reveal antiferromagnetic (AFM) spin fluctuations that are peaked at a wave vector of Q(AFM)=(1/2,1/2,1) and possess a large energy scale. These stripe spin fluctuations are similar to those found in AFe2As2 compounds, where spin-density wave AFM is driven by Fermi surface nesting between electron and hole pockets separated by Q(AFM). SrCo2As2 has a more complex Fermi surface and band-structure calculations indicate a potential instability toward either a ferromagnetic or stripe AFM ground state. The results suggest that stripe AFM magnetism is a general feature of both iron and cobalt-based arsenides and the search for spin fluctuation-induced unconventional superconductivity should be expanded to include cobalt-based compounds.

Behavior and handling of physically and immunologically castrated market pigs on farm and going to market.

Physical castration is a common management practice on commercial swine farms in the United States to reduce the incidence of boar taint and aggressive behavior. One alternative to physical castration (PC) is to immunologically castrate (IC) male pigs by blocking the gonadotropin-releasing factor (GnRF), thereby reducing levels of LH, FSH, testosterone, and androstenone. The objectives of this study were to evaluate the effects of IC on pig behavior, human-pig interactions, and handling during and after transport. Pigs were given the first immunization at wk 7 of the grower-finisher period, and second immunizations were given at wk 11, 13, or 14 of the grower-finisher period. Behaviors of PC and IC barrows were sampled at 3 time points after entering finishing at 9 wk of age: 7 wk before first injection, 16 wk (after immunization was complete) into finishing, and 1 d before marketing (16 to 19 wk into finishing). Handling during loading and unloading of trailers going to market was also quantified. Before the first injection, intact males showed increased aggression (P=0.014) and mounting (P=0.048), whereas PC barrows spent more (P=0.003) time feeding than intact males. There were treatment×time interactions for lying (P=0.018), aggression (P<0.001), and standing (P=0.009) behaviors. Few differences were observed in pig-human interactions between PC and IC barrows, with IC and PC approaching people in the same amount of time, but IC barrows were more (P<0.001) aggressive in chewing and rubbing on the test person's pant leg and boots. When handling and loading for processing in the home barn, PC barrows were more (P<0.05) vocal than IC barrows. Fewer dead and down pigs were observed among IC (0%) compared with PC barrows (1.17%). Immunological castration may result in similar or improved animal welfare compared to the stress of physical castration without pain relief.

Coexistence of half-metallic itinerant ferromagnetism with local-moment antiferromagnetism in Ba0.60K0.40Mn2As2.

Magnetization, nuclear magnetic resonance, high-resolution x-ray diffraction, and magnetic field-dependent neutron diffraction measurements reveal a novel magnetic ground state of Ba0.60K0.40Mn2As2 in which itinerant ferromagnetism (FM) below a Curie temperature TC≈100 K arising from the doped conduction holes coexists with collinear antiferromagnetism (AFM) of the Mn local moments that order below a Néel temperature TN=480 K. The FM ordered moments are aligned in the tetragonal ab plane and are orthogonal to the AFM ordered Mn moments that are aligned along the c axis. The magnitude and nature of the low-T FM ordered moment correspond to complete polarization of the doped-hole spins (half-metallic itinerant FM) as deduced from magnetization and ab-plane electrical resistivity measurements.

2011 and 2012 Early Careers Achievement Awards: farm and pig factors affecting welfare during the marketing process.

The objective of this paper is to review the scientific literature to identify on-farm factors that contribute to market weight pig transportation losses. Transportation of market weight pigs is an essential element to the multisite pork production model used in the United States. In 2011 alone, approximately 111 million market weight pigs were transported from the finishing site to the abattoir. For pigs, the marketing process can present a combination of potentially novel, physical, and/or unfamiliar experiences that can be stressful. If the pig cannot cope with these sequential and additive stressors, then an increased rate of transportation losses could occur with a detrimental effect on pork carcass value. Current yearly estimates for transport losses are 1 million pigs (1%). A variety of market weight pig and farm factors have been reported to detrimentally affect transportation losses. By understanding how pigs interact with their environment during marketing, researchers, producers, and personnel at the abattoir may begin to identify, prioritize, and attempt to minimize or eliminate these stressors. This process will ultimately decrease transportation losses, improve pork quality, and increase profitability.

Stress level among the geriatric population of urban area in eastern Nepal.

Stress is part of everyone's life which may be severe in geriatric population due to multiple and interrelated factors. A cross sectional study was carried out among hundred geriatric people living in an urban area of Dharan with an aim of identifying the level of stress in this population and to find out its association with different demographic variables. Convenient sampling technique was used to collect data. Instrument containing twenty five questions related to physical, psychological and socioeconomic stress was used. Data was analyzed by using percentage, frequency and inferential statistics (Chi- square test). Out of hundred respondents 67% were in the age group of 65 to 75 years. Fifty one percent of the respondents' had moderate stress, 40% had mild stress and remaining 9% had severe stress. Stress was significantly associated with variables such as age, education level, personal income, and financial dependence. Overall result is that geriatric population experience moderate to severe stress which varies in severity. The study findings call for the attention from concerned authorities to plan appropriate measures in order to minimize the stress among geriatric populations. Hence, their life can become productive and they can have improved quality of life.

Indoor air pollution from solid fuels and risk of upper aerodigestive tract cancers in central and eastern Europe.

BACKGROUND: Indoor air pollution from solid fuels is a potentially important risk factor for cancer, yet data on cancers from organs other than the lung are scarce. We investigated if indoor air pollution from coal and wood are risk factors for additional cancers, particularly that of the upper aerodigestive tract (oral cavity, larynx, pharynx and esophagus) in the high-risk areas of central and eastern Europe. METHODS: We used data from multi-center hospital-based case-control study of 1065 histologically confirmed upper aerodigestive tract cancer cases and 1346 controls. Standardized questionnaires were used to collect information on residential fuel use for cooking and heating. Using unconditional logistic regression, we calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) for upper aerodigestive tract cancer risk after adjusting for potential confounders. RESULTS: Lifelong wood use was associated with pharyngeal and esophageal (OR 4.05, 95% CI: 1.30-12.68 and OR 2.71, 95% CI: 1.21-6.10, respectively). We observed an exposure-response relationship between duration of wood use and risk of pharyngeal cancer among those who had never used coal (P(trend)=0.04), ruling out the possibility of residual confounding by coal. Similarly, we observed an increased risk of laryngeal cancers and head & neck cancers among those who always used coal, with a noted exposure-response relationship (P(trend)<0.01). CONCLUSIONS: Our results suggest a possible role of indoor air pollution from solid fuel use in head and neck carcinogenesis in the high risk area of central and eastern Europe.

Comparative study of sensitivity of rapid diagnostic (hexagon) test with calculated malarial parasitic density in peripheral blood.

BACKGROUND: Different diagnostic test kits are used for rapid diagnosis of malaria. Most are based on antigen detection (pLDH, Pan Aldolase, HRP-2). In context of Nepal the diagnostic reliability and sensitivity of these tests is unknown. Hexagon Malaria Combi™ is one of the most commonly used test kit in Nepal for rapid diagnosis of malaria. The aim of the present study is to evaluate the sensitivity of the Hexagon malaria Combi test in comparison with parasitic density by microscopy technique. METHODS: A Cross sectional prospective study was conducted in three districts of Nepal from September to November 2009. Blood samples were collected from the suspected cases of malaria. Thick and thin smear were prepared from all the samples and Giemsa stain was done. Simultaneously RDT (hexagon) for malaria was done. When RDT was found to be positive, blood was serially diluted in 6 tubes as 1:2, 1:4, 1:8, 1:16, 1:32 and 1:64. RDT was done on diluted blood till RDT test gave negative result. Parasitic density was calculated for undiluted and diluted blood samples and sensitivity of RDT in various parasitic densities was calculated. RESULTS: Hexagon malaria combi test is sensitive (86%) when malarial parasitic density is >500/µl. Sensitivity was found to be directly related to parasitic density. Its sensitivity is very low (2.9%) when parasitic density is less than 500/ µl. CONCLUSIONS: The sensitivity of rapid diagnostic test (hexagon Combi test detecting malarial pLDH antigen) is high only if the parasitic density is more than 500/µl.